As textile substrates age, their color tends to fade or yellow due to exposure to light, air, soil, and natural degradation of the fibers that comprise the substrates. To counteract this unwanted effect, laundry detergent manufacturers incorporate shading dyes into their products. The purpose of shading dyes is typically to counteract the fading and yellowing of the textile substrates by providing a blue-violet hue to the laundered fabrics, reducing the visual impact of the yellowing. There are many disclosures of shading dyes in detergents. Generally shading dyes are effective for shading a specific textile type, either cotton or synthetic fabrics, specifically polyester. Mixtures of dyes or dyes and pigments are generally needed to effect shading across a range of textiles, as is described in WO2006/32327 and WO2008/090091.
There is therefore still a need to find dyes that will provide deposition across different types of fibres, such as cotton and synthetic fibres such as nylon and/or polyester and it is desirable to find dyes that deposit substantially evenly across different textile types and even mixed fibre types, such as polycotton. The present invention has been found to alleviate this problem. Furthermore the present invention provides compositions that are advantageous in providing a hueing effect, for example, a whitening effect to fabrics, while not building up over time and causing undesirable discoloration to the treated fabrics.